It's pretty plainly referring to page 24 in a different document (the "instruction booklet"). I wouldn't expect that to be the same PDF file (although the IRS form download page might be the subject of a different "This is broken" entry, if they haven't improved it since last year.)

Posted by: Mark Gritter at April 15, 2005 02:11 AM

A related issue, definitely broken: Documents designed for print booklets often have page numbers on them. When those documents are converted to PDF, the page numbers stay, but the PDF file has its own page numbering. In many cases, those page numbers will not match.

It's very annoying to go through an 80-page PDF file, trying to guess which PDF page matches up with the page 20 listed in the table of contents.

Posted by: Kelson at April 15, 2005 04:29 AM

"I wouldn't expect that to be the same PDF file."

You are just anticipating its brokenness!

Posted by: Reed at April 15, 2005 11:29 AM

This does reiterate the point that what is broken for one is not broken for all (probably why there are always a few "that's not broken!" comments posted, as well).

Similar example: My mother got into downloadable PDF e-Books. Each chapter is a separate PDF file. The e-Book reader software handles the multiple files brilliantly and seamlessly (to me) and completely confusingly and annoyingly (to her). It tells us that we're on page 146 of 757 of the book and page 14 of 37 of the file.

I think that's perfect design: It doesn't tell you simply that you're on some arbitrary page 14 of whatever chapter you're in when you want to know how far through the entire book you are (like a standard PDF reader like Acrobat or Preview would), and it doesn't limit you to only knowing that you're on page 146 of a 757 page book when what you really want to know is how far through the chapter you are.

My mother hates it. It took me a while to figure out why, but we finally boiled it down to this: She gets confused between the "book" construct and the fact that each chapter is a different "file." Even though the reader allows seamless switching between chapters (as far as I can tell it keeps three files in memory at any given time), the use of the word "file" throws her for a loop since she's used to a complete document being one file in her word processor. At the same time, the printed page numbers on each page (or page image, if you want to get technical about it) don't match either the chapter pagination or the book pagination as reflected in the reader. She can't grasp how one page has three different page numbers.

My milestone for design has always been "can my mother use it?" Trying to explain computer concepts to an septuagenarian 1600 miles away has called this metric into question more than once as she manages to make software do things it was never intended to do and invokes strange and bizarre behavior from her hardware I've never seen before in my life. If anyone wants to hire the ultimate beta-tester, I'll hook you up with my mom.

Point being, it is difficult to be all things to all people. I prefer to have all the information possible in front of me, she finds that overwhelming and wants to be able to select only the bit of information she wants.

In this case (see, this IS all on topic!) all that would be required is a hyperlink to the relevant portion of the relevant document. PDF supports it, so why not simply allow a single click to take the user directly to the information required? This even my mother could understand!

Posted by: Erich at April 15, 2005 02:31 PM

Well, I agree that the best solution is to have instructions accessible from wherever you're entering the numbers. The model of filling out a PDF that's the exact equivalent of the paper form is questionable; California's web-based electronic filing was very not-broken.

I still don't think it's reasonable to assume that you can type any page number reference into the PDF navigation--- at some point there really are different documents that have to be accessed by external links.

Posted by: Mark Gritter at April 16, 2005 12:34 AM

PDF supports using different numbering schemes for different sections of a document. For example, you can number the preface, table of contents, etc. "i", "ii", ... and the page that has "1" on it will be page 1 and all the page numbers in the text will work fine.

Most producers of PDF files don't go to the trouble of doing this, however.

Posted by: Larry Rosenstein at April 17, 2005 07:32 PM